src/com/android/settings/Utils.java

/**
 * Copyright (C) 2007 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy
 * of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package com.android.settings;

import java.util.List;

import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.Resources;
import android.content.res.Resources.NotFoundException;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.SystemProperties;
import android.preference.Preference;
import android.preference.PreferenceGroup;
import android.telephony.TelephonyManager;
import android.text.TextUtils;

public class Utils {

    /**
     * Set the preference's title to the matching activity's label.
     */
    public static final int UPDATE_PREFERENCE_FLAG_SET_TITLE_TO_MATCHING_ACTIVITY = 1;

    /**
     * Name of the meta-data item that should be set in the AndroidManifest.xml
     * to specify the icon that should be displayed for the preference.
     */
    private static final String META_DATA_PREFERENCE_ICON = "com.android.settings.icon";

    /**
     * Name of the meta-data item that should be set in the AndroidManifest.xml
     * to specify the title that should be displayed for the preference.
     */
    private static final String META_DATA_PREFERENCE_TITLE = "com.android.settings.title";

    /**
     * Name of the meta-data item that should be set in the AndroidManifest.xml
     * to specify the summary text that should be displayed for the preference.
     */
    private static final String META_DATA_PREFERENCE_SUMMARY = "com.android.settings.summary";

    /**
     * Finds a matching activity for a preference's intent. If a matching
     * activity is not found, it will remove the preference.
     *
     * @param context The context.
     * @param parentPreferenceGroup The preference group that contains the
     *            preference whose intent is being resolved.
     * @param preferenceKey The key of the preference whose intent is being
     *            resolved.
     * @param flags 0 or one or more of
     *            {@link #UPDATE_PREFERENCE_FLAG_SET_TITLE_TO_MATCHING_ACTIVITY}
     *            .
     * @return Whether an activity was found. If false, the preference was
     *         removed.
     */
    public static boolean updatePreferenceToSpecificActivityOrRemove(Context context,
            PreferenceGroup parentPreferenceGroup, String preferenceKey, int flags) {

        Preference preference = parentPreferenceGroup.findPreference(preferenceKey);
        if (preference == null) {
            return false;
        }

        Intent intent = preference.getIntent();
        if (intent != null) {
            // Find the activity that is in the system image
            PackageManager pm = context.getPackageManager();
            List<ResolveInfo> list = pm.queryIntentActivities(intent, 0);
            int listSize = list.size();
            for (int i = 0; i < listSize; i++) {
                ResolveInfo resolveInfo = list.get(i);
                if ((resolveInfo.activityInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM)
                        != 0) {

                    // Replace the intent with this specific activity
                    preference.setIntent(new Intent().setClassName(
                            resolveInfo.activityInfo.packageName,
                            resolveInfo.activityInfo.name));

                    if ((flags & UPDATE_PREFERENCE_FLAG_SET_TITLE_TO_MATCHING_ACTIVITY) != 0) {
                        // Set the preference title to the activity's label
                        preference.setTitle(resolveInfo.loadLabel(pm));
                    }

                    return true;
                }
            }
        }

        // Did not find a matching activity, so remove the preference
        parentPreferenceGroup.removePreference(preference);

        return true;
    }

    /**
     * Finds a matching activity for a preference's intent. If a matching
     * activity is not found, it will remove the preference. The icon, title and
     * summary of the preference will also be updated with the values retrieved
     * from the activity's meta-data elements. If no meta-data elements are
     * specified then the preference title will be set to match the label of the
     * activity, an icon and summary text will not be displayed.
     *
     * @param context The context.
     * @param parentPreferenceGroup The preference group that contains the
     *            preference whose intent is being resolved.
     * @param preferenceKey The key of the preference whose intent is being
     *            resolved.
     *
     * @return Whether an activity was found. If false, the preference was
     *         removed.
     *
     * @see {@link #META_DATA_PREFERENCE_ICON}
     *      {@link #META_DATA_PREFERENCE_TITLE}
     *      {@link #META_DATA_PREFERENCE_SUMMARY}
     */
    public static boolean updatePreferenceToSpecificActivityFromMetaDataOrRemove(Context context,
            PreferenceGroup parentPreferenceGroup, String preferenceKey) {

        IconPreferenceScreen preference = (IconPreferenceScreen)parentPreferenceGroup
                .findPreference(preferenceKey);
        if (preference == null) {
            return false;
        }

        Intent intent = preference.getIntent();
        if (intent != null) {
            // Find the activity that is in the system image
            PackageManager pm = context.getPackageManager();
            List<ResolveInfo> list = pm.queryIntentActivities(intent, PackageManager.GET_META_DATA);
            int listSize = list.size();
            for (int i = 0; i < listSize; i++) {
                ResolveInfo resolveInfo = list.get(i);
                if ((resolveInfo.activityInfo.applicationInfo.flags
                        & ApplicationInfo.FLAG_SYSTEM) != 0) {
                    Drawable icon = null;
                    String title = null;
                    String summary = null;

                    // Get the activity's meta-data
                    try {
                        Resources res = pm
                                .getResourcesForApplication(resolveInfo.activityInfo.packageName);
                        Bundle metaData = resolveInfo.activityInfo.metaData;

                        if (res != null && metaData != null) {
                            icon = res.getDrawable(metaData.getInt(META_DATA_PREFERENCE_ICON));
                            title = res.getString(metaData.getInt(META_DATA_PREFERENCE_TITLE));
                            summary = res.getString(metaData.getInt(META_DATA_PREFERENCE_SUMMARY));
                        }
                    } catch (NameNotFoundException e) {
                        // Ignore
                    } catch (NotFoundException e) {
                        // Ignore
                    }

                    // Set the preference title to the activity's label if no
                    // meta-data is found
                    if (TextUtils.isEmpty(title)) {
                        title = resolveInfo.loadLabel(pm).toString();
                    }

                    // Set icon, title and summary for the preference
                    preference.setIcon(icon);
                    preference.setTitle(title);
                    preference.setSummary(summary);

                    // Replace the intent with this specific activity
                    preference.setIntent(new Intent().setClassName(
                            resolveInfo.activityInfo.packageName,
                            resolveInfo.activityInfo.name));

                   return true;
                }
            }
        }

        // Did not find a matching activity, so remove the preference
        parentPreferenceGroup.removePreference(preference);

        return false;
    }

    /**
     * Returns true if Monkey is running.
     */
    public static boolean isMonkeyRunning() {
        return SystemProperties.getBoolean("ro.monkey", false);
    }

    /**
     * Returns whether the device is voice-capable (meaning, it is also a phone).
     */
    public static boolean isVoiceCapable(Context context) {
        TelephonyManager telephony =
                (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
        return telephony != null && telephony.isVoiceCapable();
    }
}